CPA Flow Conditioners for Liquid Applications

The CPA lineup of flow conditioners are an effective solution for liquid measurement applications. This applies to all types of volumetric flow meters; ultrasonic, turbine, orifice, or venturi.

CPA 50E/65E vs. AGA 3 19-Tube Bundles

In liquid applications, the CPA 50E and 65E can actually have a lower pressure drop than typical tube bundles or straightening vanes. The design of the tube bundle is detrimental in applications with high viscosity fluids due to the significant increase in pipe wall friction in the flow conditioner passages.

CPA Flow Conditioners for Liquid Applications

Pressure loss coefficient of CPA 50E vs AGA 3 19‐Tube Bundle across a range of fluid measurement scenarios.

Perforated plate flow conditioners such as the CPA 50E & 65E will outperform typical straightening vanes and AGA 3 tube bundles in certain liquid measurement applications. The CPA 50E and 65E can restore fully developed, swirl free flow in fluids with Reynolds numbers ranging from 300 to 30000000.

Flow Profiles

Flow profiles generated by the CPA 50E across a Reynolds number range of 300 – 30000000.

Liquid vs. Gas & Reynolds Number

Many applications are sensitive to the differences between liquid and gas phases; the phases can behave differently and must therefore be treated differently. This is important in many industrial applications since fluid phase can have a significant effect on the fluid behavior, process design, and equipment.

However, flow measurement is concerned specifically with fluid dynamics; how a fluid moves through a pipeline. In this type of application, gases and liquids behave in very much the same manner. Pipeline fluid dynamics and flow measurement does not care about whether a fluid is in a gaseous or liquid phase.

Instead, flow measurement is primarily affected by a property known as the Reynold’s Number. It is a dimensionless number that allows for instant comparison between the behavior of any fluid, regardless of whether it is a gas or liquid. Whether the fluid is natural gas, air, water, fuel oil, LNG, or crude oil, the flow behavior can be described using the Reynold’s Number.

Reynolds Number Equation
  • ρ = Bulk fluid density, kg/m3.
  • V = Bulk fluid velocity, m/s.
  • L = Cross sectional diameter of fluid flow, m.
  • μ = Bulk fluid dynamic viscosity, Pa * s.

Laminar vs. Turbulent Flow

Reynolds number helps us distinguish between laminar and turbulent fluids. Laminar flows are applications where the flow viscosity and pipe wall friction overwhelms other flow behaviors. It is typically found in very slow, thick fluids such as crude oil applications. Turbulent flow is when the random turbulent movement of the flow overwhelms the viscosity and wall friction. It is found in fast flowing situations with fluids such as water, light petroleum liquids, air or natural gas. Laminar flow is typically for a Reynolds number range of 100 – 2500 while turbulent fluids have Reynolds numbers above 5000.

From a flow measurement standpoint, Reynolds number changes the shape of the velocity flow profile that is being measured. Turbulent flows have a flat flow profile due to higher inertial mixing forces and lower wall friction while laminar flows have more peaky flow profiles due to a lack of inertial mixing and high wall friction. The CPA 50E is able to restore flow profiles in either scenario.

Laminar vs Turbulent Flow

Showing the development of a velocity flow profile due to laminar and turbulence fluid forces.

For further information, do not hesitate to contact our experienced sales representatives, who will be able to help you choose the correct product for your specific needs.

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